Micro-honeycomb tube type series reactor for synthesizing hydrocarbon and preparation method of micro-honeycomb tube type series reactor

Abstract

The invention relates to a micro honeycomb tube type series reactor for synthesizing hydrocarbon and a preparation method thereof, the preparation method comprises the following steps: preparing a fuel electrode blank body by a phase inversion assisted extrusion method, and forming a plurality of channels in the fuel electrode blank body by a spinning head for extrusion with a plurality of needle cores; sintering the fuel electrode blank body under a high-temperature condition to obtain a fuel electrode with a plurality of channels inside; an electrolyte layer is arranged on the surface of the fuel electrode, an air electrode is arranged on the surface of the electrolyte layer, and a fixed oxide electrolytic cell unit is formed; loading a catalyst in the fuel electrode by adopting an impregnation method to form a hydrocarbon preparation unit, and distributing the hydrocarbon preparation unit and the fixed oxide electrolytic cell unit along the axial direction of the fuel electrode; the catalyst is a copper-based catalyst, and copper in the loaded catalyst exists in the form of cuprous oxide. The technical problems that hydrocarbon products are single and low in value in the application process of an existing single-channel reactor are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical carbon dioxide conversion to hydrocarbons, and in particular to a micro-honeycomb tube-type series reactor for synthesizing hydrocarbons and a preparation method thereof. Background Art

[0002] At present, CO2 conversion technologies mainly include photocatalytic conversion, biological conversion, thermal catalytic conversion, and electrochemical conversion, etc. Among them, electrochemical conversion is considered to be a CO2 conversion means with great application prospects because it can be carried out under relatively mild conditions and can be directly driven by renewable energy (such as wind energy and solar energy).

[0003] Electrochemical CO2 conversion usually relies on an electrolytic cell to carry out the reaction. According to different electrolyte types, it can be divided into a proton exchange membrane electrolytic cell (PEMEC), an alkaline electrolytic cell (AEC), and a solid oxide electrolytic cell (SOEC). Among them, the working temperature of SOEC is relatively high, usually working in the range of 600 - 850 °C. Compared with PEMEC and AEC, which usually work within 60 - 160 °C, SOEC has two major advantages: more favorable thermodynamics and faster kinetics. In terms of thermodynamics, the energy required for electrolysis and the electrolysis voltage both decrease with the increase of temperature, thereby reducing energy consumption. In terms of kinetics, a higher working temperature can accelerate the reaction rate of the electrode, significantly reduce the electrode polarization voltage, and thus reduce energy loss during electrolysis. Therefore, SOEC has higher efficiency and lower cost advantages compared with low-temperature electrolytic cells.

[0004] During the working process, SOEC co-electrolyzes carbon dioxide and water vapor into syngas (CO and H 2 ), and the syngas can be used to produce high-value hydrocarbons through the Fischer-Tropsch process. However, since the working temperature of SOEC is usually between 650 - 800 °C, and the working temperature for preparing hydrocarbons through the Fischer-Tropsch process is usually below 350 °C, the above two processes are usually completed in two independent reactors. In the prior art, although there are technical solutions that can complete the high-temperature carbon dioxide and water vapor co-electrolysis and low-temperature methanation catalysis in one system, the reactor used is a single-channel tube structure. On the one hand, the reaction area provided by it is limited, which limits the catalytic activity of the reactor. On the other hand, due to the limitations of the composition, structure, and application method of the reactor, the generated hydrocarbons are only methane with relatively low value, and the value of hydrocarbons cannot be effectively improved. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a micro-honeycomb tube-type series reactor for synthesizing hydrocarbons and a preparation method thereof, which solves the technical problems of single and low-value hydrocarbon products in the application process of the existing single-channel reactor.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A preparation method of a microcellular tubular series reactor for synthesizing hydrocarbons, comprising:

[0008] Preparing a fuel electrode green body by a phase inversion assisted extrusion method, and the spinneret for extrusion has a plurality of needle cores, so that a plurality of channels are formed in the fuel electrode green body;

[0009] Sintering the fuel electrode green body under high temperature conditions to obtain a fuel electrode with a plurality of channels inside;

[0010] Setting an electrolyte layer on the surface of the fuel electrode, and setting an air electrode on the surface of the electrolyte layer to form a solid oxide electrolytic cell unit;

[0011] Loading a catalyst in the fuel electrode by an impregnation method to form a hydrocarbon preparation unit, which is distributed along the axial direction of the fuel electrode with the solid oxide electrolytic cell unit, thereby forming the series reactor;

[0012] The catalyst is a copper-based catalyst, and copper in the catalyst exists in the form of cuprous oxide after loading;

[0013] Connecting the two axial ends of the fuel electrode and the two axial ends of the air electrode of the series reactor to an electrochemical workstation through silver wires respectively. Under the set temperature conditions, the series reactor is used to convert carbon dioxide and water vapor into hydrocarbons, and the hydrocarbons are a mixture including methane, ethane, ethylene, and propane.

[0014] The further technical solution is:

[0015] The number of channels in the fuel electrode is 4 to 7; the thickness of the thinnest part of the outer wall of the fuel electrode is 50 - 80 μm.

[0016] The method of loading the catalyst in the fuel electrode by an impregnation method includes:

[0017] Uniformly mixing copper nitrate or at least one mixture of ruthenium nitrate, cerium nitrate, and nickel nitrate with copper nitrate and deionized water in proportion to obtain a catalyst solution;

[0018] Placing a part of the fuel electrode near its first end in the catalyst solution for impregnation, taking it out after reaching the set time, and then successively performing drying and sintering treatments;

[0019] Repeating the impregnation process until the catalyst loading amount is 25% of the total mass of the series reactor.

[0020] The method of setting the electrolyte layer on the surface of the fuel electrode includes:

[0021] Yttria-stabilized zirconia powder, polyvinyl butyral resin, polyethylene glycol, a dispersant, and an ethanol solution are uniformly mixed in proportion to form an electrolyte slurry.

[0022] The electrolyte slurry is disposed on the circumferential surface of the fuel electrode near its second end by dip coating.

[0023] Then, drying and sintering treatments are performed in sequence.

[0024] The setting of the air electrode on the surface of the electrolyte layer includes:

[0025] Yttria-stabilized zirconia powder, lanthanum strontium cobalt iron powder, and an ethylene glycol solution are uniformly mixed in a mass ratio of 5:5:6 to prepare an air electrode slurry.

[0026] The air electrode slurry is sprayed or brushed on the surface of the electrolyte layer.

[0027] Then, drying and sintering treatments are performed in sequence.

[0028] The preparation of the fuel electrode green body by the phase inversion assisted extrusion method includes:

[0029] Nickel powder, yttria-stabilized zirconia powder, N-methylpyrrolidone, and a dispersant are mixed in proportion and ball milled in a ball mill to obtain a first membrane liquid.

[0030] Polymethyl methacrylate is added to the first membrane liquid and ball milled continuously in the ball mill to obtain a second membrane liquid.

[0031] The second membrane liquid is subjected to vacuum degassing treatment and used as the shell liquid, and the coagulant is used as the core liquid, and they are simultaneously extruded into water through the spinneret to obtain the fuel electrode green body.

[0032] The mass ratio of the nickel powder, yttria-stabilized zirconia powder, N-methylpyrrolidone, dispersant, and polymethyl methacrylate is (120 - 150):(80 - 100):(90 - 110):(1 - 2):(30 - 45).

[0033] The temperature for sintering the fuel electrode green body under high temperature conditions is 1200 °C; the heating rate and cooling rate during the sintering process are 5 °C / min.

[0034] The set temperature conditions include: maintaining the solid oxide electrolysis cell unit at 750 °C, and forming a temperature gradient of 750 °C to 150 °C on the hydrocarbon production unit.

[0035] A micro-honeycomb tube-type series reactor for synthesizing hydrocarbons prepared by the preparation method described above.

[0036] The beneficial effects of the present invention are as follows:

[0037] The present invention combines two independent processes of high-temperature co-electrolysis of CO 2 and H 2 O to prepare syngas and the preparation of hydrocarbons from syngas together, avoiding the separation and purification of intermediate products (syngas), and being able to make full use of the waste heat of high-temperature electrolysis to heat the hydrocarbon preparation unit, improving the energy efficiency.

[0038] The micro-honeycomb (i.e., multi-channel) tubular series reactor prepared by the present invention is superior to the traditional single-channel series reactor in terms of structural design and performance. Specifically, it has the following advantages:

[0039] Based on loading a copper-based catalyst in the hydrocarbon preparation unit of the present invention and combining the advantage that the reactants are more uniform with the micro-honeycomb structure, the hydrocarbon preparation unit of the series reactor realizes the production of methane, ethane, ethylene, and propane under the combined action of electrocatalysis and thermal catalysis. Compared with the traditional series reactor that only generates methane as the hydrocarbon, with low product value, the present invention realizes the conversion of CO 2 / CO to high-value hydrocarbons such as ethane, ethylene, and propane.

[0040] In the hydrocarbon preparation unit of the present invention, copper elements exist in the form of cuprous oxide, and cuprous oxide can promote C-C coupling. The micro-honeycomb structure provides a larger surface area, providing suitable conditions for cuprous oxide to promote C-C coupling, and effectively avoiding the inactivation of the catalyst caused by agglomeration, thereby realizing the effective conversion of CO and CO 2 to high-value hydrocarbons such as ethane, ethylene, and propane.

[0041] The multi-channel micro-honeycomb design of the present invention not only significantly improves the mechanical strength but also optimizes the gas flow characteristics. Among them, at the solid oxide electrolysis cell unit, the micro-honeycomb structure effectively shortens the gas diffusion path, reduces the mass transfer resistance, thereby enhancing the gas transport rate and improving the electrolysis efficiency. At the hydrocarbon preparation unit, the micro-honeycomb structure can significantly increase the catalyst loading amount, thereby providing a larger specific surface area and more active sites, which is beneficial to improving the utilization rate and catalytic efficiency of the catalyst. In addition, this structure helps to optimize the gas flow distribution, reduce the mass transfer resistance, and make the conversion of CO2 / CO more efficient and stable. Compared with the single-channel structure, the micro-honeycomb structure can distribute the reactants more evenly, improve the utilization rate of the catalyst, thereby enhancing the synthesis rate and selectivity of hydrocarbons and achieving better catalytic performance.

[0042] Other features and advantages of the present invention will be described in the subsequent description or will be understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic structural diagram of the microcellular tubular series reactor according to an embodiment of the present invention.

[0044] Figure 2 This is an SEM image of the fuel electrode according to an embodiment of the present invention.

[0045] Figure 3 This is an SEM image of the fuel electrode loaded with a catalyst at the hydrocarbon preparation unit according to an embodiment of the present invention.

[0046] Figure 4 This is a schematic structural diagram of the series reactor for hydrocarbon preparation according to an embodiment of the present invention.

[0047] In the figure: 1. Fuel electrode; 2. Electrolyte layer; 3. Air electrode; 4. Solid oxide electrolysis cell unit; 5. Hydrocarbon preparation unit; 6. Alumina tube; 7. Ceramic glue; 61. Intake end; 62. Outlet end. Detailed implementation manners

[0048] The following describes the detailed implementation manners of the present invention with reference to the accompanying drawings.

[0049] See Figure 1 , a preparation method of a microcellular tubular series reactor for synthesizing hydrocarbons according to the present application, includes:

[0050] Preparing a fuel electrode green body by the phase inversion assisted extrusion method, and the spinneret for extrusion has a plurality of needle cores, so that a plurality of channels are formed in the fuel electrode green body;

[0051] Sintering the fuel electrode green body under high temperature conditions to obtain a fuel electrode 1 with a plurality of channels inside;

[0052] Setting an electrolyte layer 2 on the surface of the fuel electrode, and setting an air electrode 3 on the surface of the electrolyte layer to form a solid oxide electrolysis cell unit 4;

[0053] Loading a catalyst into the fuel electrode by the impregnation method to form a hydrocarbon preparation unit 5, which is axially distributed along the fuel electrode 1 with the solid oxide electrolysis cell unit 4, thereby forming the series reactor;

[0054] The catalyst includes at least one of ruthenium nitrate, copper nitrate, cerium nitrate, and nickel nitrate;

[0055] Axially connecting both ends of the fuel electrode 1 and both ends of the air electrode 3 of the series reactor to an electrochemical workstation through silver wires. At a set temperature, the series reactor is used to convert carbon dioxide and water vapor into hydrocarbons, and the hydrocarbons are a mixture including methane, ethane, ethylene, and propane.

[0056] The fuel electrode green body prepared in this application is a porous structure obtained by a phase inversion assisted extrusion method. Preferably, the fuel electrode green body is sintered at a high temperature of 1200 °C, and the heating rate and cooling rate during the sintering process are 5 °C / min. The SEM image of the fuel electrode 1 with multiple channels inside is as shown in Figure 2 shown. The multi-channel fuel electrode 1 is shaped like a honeycomb, so this application names it a "micro-honeycomb tube" structure. This structure helps to optimize the gas flow distribution and reduce the mass transfer resistance. And it can provide more reaction sites and enhance the catalytic ability of the reactor.

[0057] The number of channels in the fuel electrode 1 is 4 to 7, preferably 4. Due to the large number of channels, the outer wall thickness of the fuel electrode 1 in this application is relatively thin, and the thinnest part is preferably 50-80 μm thick. Compared with the traditional single-channel structure, the transmission rate of gas diffusing from the flow channel to the electrolyte layer in the solid oxide electrolysis cell unit 4 can be greatly improved. The hydrocarbon preparation unit 5 can load more catalysts and provide more reaction sites, enhancing the synthesis rate of hydrocarbons. The SEM image of the fuel electrode in the hydrocarbon preparation unit 5 after loading the catalyst is as shown in Figure 3 shown.

[0058] This application loads a copper-based catalyst in the hydrocarbon preparation unit 5. Combining with the multi-channel structure of the fuel electrode 1 enables the reactants to act more uniformly in synergy. In the application of converting carbon dioxide and water vapor into hydrocarbons, it realizes the conversion of CO 2 / CO to high-value hydrocarbons such as ethane, ethylene, and propane. It makes up for the problem of low single value of products in traditional methods.

[0059] The technical solution of this application will be further described below with specific examples.

[0060] Example 1

[0061] This example provides a micro-honeycomb tube series reactor for synthesizing hydrocarbons and its preparation method, including the following steps:

[0062] S1. Fuel electrode preparation:

[0063] 120 g of nickel powder, 80 g of yttria-stabilized zirconia powder, and 1 g of dispersant are dissolved in 90 g of N-methylpyrrolidone solution, placed in a ball mill and ball milled for 24 h to obtain a first membrane solution, and then 30 g of polymethyl methacrylate is added and ball milled for another 24 h to obtain a second membrane solution;

[0064] The second membrane solution is subjected to a 2 h vacuum degassing treatment;

[0065] 20 g of polyvinyl alcohol is dissolved in 280 g of deionized water as a coagulant;

[0066] Using the second membrane solution as the shell solution and the coagulant as the core solution, the shell solution and the coagulant are simultaneously extruded into water through a spinning head with four needle cores to obtain a fuel electrode embryo with a length of 18 cm and four channels; wherein the flow rate of the shell solution is 9 ml / min and the flow rate of the core solution (coagulant) is 15 ml / min;

[0067] The fuel electrode embryo is sintered at 1200 °C for 4 h, and the heating rate and the cooling rate are 5 °C / min to obtain a porous fuel electrode as the support.

[0068] S2. Set up the electrolyte layer:

[0069] Yttria-stabilized zirconia powder, polyvinyl butyral resin, polyethylene glycol, dispersant, and ethanol solution are formulated into a solution according to a mass ratio of 12:1:1:1:75, and ball-milled in a ball mill for 24 h to obtain an electrolyte slurry;

[0070] The electrolyte slurry is impregnated at a position 1 cm from one end face of the fuel electrode, and the impregnation length is 5 cm. After drying, it is sintered at 1500 °C for 5 h to obtain a dense electrolyte layer.

[0071] S3. Set up the air electrode:

[0072] 10 g of yttria-stabilized zirconia powder and 10 g of lanthanum strontium cobalt iron powder are uniformly mixed in 12 g of ethylene glycol solution to obtain an air electrode slurry;

[0073] The outer layer of the electrolyte layer is covered with an air electrode 2 cm long by brushing or spraying;

[0074] After drying, it is sintered at 1000 °C for 2 h to obtain a solid oxide electrolysis cell unit.

[0075] S4. Load the catalyst:

[0076] Copper nitrate is dissolved in deionized water to prepare a 5 M aqueous solution of copper nitrate, that is, a catalyst slurry is obtained;

[0077] Approximately 6 cm long of the other end of the fuel electrode away from the solid oxide electrolysis cell unit is placed in the catalyst slurry, and impregnation is carried out under vacuum. After impregnation for 1 h, it is dried at 80 °C for 12 h and then sintered at 500 °C for 10 min; the catalyst impregnation step is repeated until the catalyst loading is 25% of the total mass of the reactor; after completion of impregnation, it is sintered at 500 °C for 4 h to obtain a hydrocarbon preparation unit, and a micro-honeycomb tube-type series reactor is obtained. Among them, copper elements exist in the form of cuprous oxide. Cuprous oxide can promote C-C coupling and is beneficial to promoting the conversion of CO and CO 2 to high-value hydrocarbons such as ethane, ethylene, and propane.

[0078] See Figure 4, applying the microcellular tubular series reactor to synthesize hydrocarbons, including the following steps:

[0079] S5. Wind silver wires around both ends of the fuel electrode and both ends of the air electrode of the series reactor, fix the silver wires with silver paste to enhance current transmission, and connect the silver wires to the electrochemical workstation;

[0080] S6. Seal the part of the series reactor except the air electrode 3 in the alumina tube 6, and fill ceramic glue 7 at the sealing part, while exposing the air electrode to the air atmosphere;

[0081] S7. Place the device obtained in S6 in a constant temperature furnace at 750 °C, and pass pure hydrogen gas into the series reactor through the inlet end 61 of the alumina tube 6 to reduce the fuel electrode for 4 h;

[0082] S8. After the reduction is completed, keep the solid oxide electrolysis cell unit in the constant temperature furnace, and place the hydrocarbon preparation unit outside the constant temperature furnace to form a temperature gradient from 750 °C to 150 °C on the hydrocarbon preparation unit;

[0083] S9. Apply a constant potential of 1.5 V to the series reactor through the electrochemical workstation, and pass a mixed gas (15 vol.% CO2 - 85 vol.% H2O) with a flow rate of 50 ml / min into the series reactor.

[0084] S10. The outlet gas of the series reactor is output from the outlet end 62 of the alumina tube 6, sent to a gas chromatograph for analysis after drying, and the analysis results are shown in Table 1.

[0085] Table 1 Composition of the outlet gas of the series reactor in Example 1

[0086] <![CDATA[CO 2 > CO <![CDATA[H 2 > <![CDATA[CH 4 > <![CDATA[C 2 H 6 > <![CDATA[C 2 H 4 > <![CDATA[C 3 H 8 > 3.21％ 1.57％ 15.6％ 20.06％ 40.21％ 12.21％ 7.14％

[0087] Example 2

[0088] This example provides a microcellular tubular series reactor for synthesizing hydrocarbons and its preparation method, including the following steps:

[0089] S1. Preparation of the fuel electrode:

[0090] Dissolve 150 g of nickel powder, 100 g of yttria-stabilized zirconia powder, and 2 g of dispersant in 110 g of N-methylpyrrolidone solution, place it in a ball mill and ball mill for 24 h to obtain the first membrane liquid, and then add 33 g of polymethyl methacrylate and continue ball milling for 24 h to obtain the second membrane liquid;

[0091] Perform a 2-h vacuum degassing treatment on the second membrane liquid;

[0092] Dissolve 20 g of polyvinyl alcohol in 280 g of deionized water as a coagulant;

[0093] Using the second membrane solution as the shell solution and the coagulant as the core solution, the shell solution and the coagulant are simultaneously extruded into water through a spinning head with four needle cores to obtain a fuel electrode embryo with a length of 18 cm and four channels; wherein the flow rate of the shell solution is 9 ml / min, and the flow rate of the core solution (coagulant) is 25 ml / min.

[0094] The fuel electrode embryo is sintered at 1200 °C for 4 h, and the heating rate and the cooling rate are 5 °C / min to obtain a porous fuel electrode as the support.

[0095] S2. Setting the electrolyte layer:

[0096] Yttria-stabilized zirconia powder, polyvinyl butyral resin, polyethylene glycol, dispersant, and ethanol solution are mixed according to a mass ratio of 12:1:1:1:75 to form a solution, and ball-milled in a ball mill for 24 h to obtain an electrolyte slurry.

[0097] The fuel electrode is impregnated with the electrolyte slurry at a distance of 1 cm from one end face of the fuel electrode, and the impregnation length is 5 cm. After drying, it is sintered at 1500 °C for 5 h to obtain a dense electrolyte layer.

[0098] S3. Setting the air electrode:

[0099] 10 g of yttria-stabilized zirconia powder and 10 g of lanthanum strontium cobalt iron powder are uniformly mixed in 12 g of ethylene glycol solution to obtain an air electrode slurry.

[0100] The outer layer of the electrolyte layer is covered with an air electrode with a length of 2 cm by brushing or spraying.

[0101] After drying, it is sintered at 1000 °C for 2 h to obtain a solid oxide electrolysis cell unit.

[0102] S4. Loading the catalyst:

[0103] Copper nitrate and cerium nitrate are accurately weighed according to a stoichiometric ratio of 1:1 and dissolved in deionized water, and citric acid is added. The molar ratio of metal ions to citric acid is 1:1.5, and uniformly stirred to form a 5 M catalyst slurry.

[0104] Approximately 6 cm long part of the other end of the fuel electrode far from the solid oxide electrolysis cell unit is placed in the catalyst slurry and impregnated under vacuum. After impregnation for 1 h, it is dried at 80 °C for 12 h and then sintered at 500 °C for 10 min; the catalyst impregnation step is repeated until the catalyst loading is 25% of the total mass of the reactor; after completion of impregnation, it is sintered at 500 °C for 4 h to obtain a hydrocarbon preparation unit, and a micro-honeycomb tube-type series reactor is obtained. Among them, copper elements exist in the form of cuprous oxide.

[0105] As an alternative, citric acid can be removed during the catalyst setting process.

[0106] According to the same application method as described in Example 1, the analysis results of the gas at the outlet of the microcellular tubular series reactor are shown in Table 2.

[0107] Table 2 Composition of the gas at the outlet of the series reactor in Example 2

[0108] <![CDATA[CO 2 > CO <![CDATA[H 2 > <![CDATA[CH 4 > <![CDATA[C 2 H 6 > <![CDATA[C 2 H 4 > <![CDATA[C 3 H 8 > 2.57％ 0.82％ 10.6％ 15.21％ 38.56％ 19.35％ 12.89％

[0109] Example 3

[0110] This example provides a microcellular tubular series reactor for synthesizing hydrocarbons and a preparation method thereof, including the following steps:

[0111] S1. Preparation of the fuel electrode:

[0112] Dissolve 135 g of nickel powder, 90 g of yttria-stabilized zirconia powder, and 1.5 g of dispersant in 100 g of N-methylpyrrolidone solution, place it in a ball mill and ball mill for 24 h to obtain the first membrane solution, and then add 35 g of polymethyl methacrylate and continue to ball mill for 24 h to obtain the second membrane solution;

[0113] Perform a 2-h vacuum degassing treatment on the second membrane solution;

[0114] Dissolve 20 g of polyvinyl alcohol in 280 g of deionized water as the coagulant;

[0115] Use the membrane solution 2 as the shell solution and the coagulant as the core solution, and simultaneously extrude the shell solution and the coagulant into water through a spinning head with four needle cores to obtain a fuel electrode embryo 18 cm long with four channels; the flow rate of the shell solution is 9 ml / min, and the flow rate of the core solution (coagulant) is 20 ml / min;

[0116] Sinter the fuel electrode embryo at 1200 °C for 4 h, with a heating rate and a cooling rate of 5 °C / min, to obtain a porous fuel electrode as the support.

[0117] S2. Set the electrolyte layer:

[0118] Prepare a solution by mixing yttria-stabilized zirconia powder, polyvinyl butyral resin, polyethylene glycol, dispersant, and ethanol solution in a mass ratio of 12:1:1:1:75, and ball mill in a ball mill for 24 h to obtain an electrolyte slurry;

[0119] Immerse the electrolyte slurry in the fuel electrode at a distance of 1 cm from one end face of the fuel electrode, with an immersion length of 5 cm, dry it, and sinter it at 1500 °C for 5 h to obtain a dense electrolyte layer.

[0120] S3. Set the air electrode:

[0121] 10 g of yttria-stabilized zirconia powder and 10 g of lanthanum strontium cobalt iron powder are uniformly mixed in 12 g of ethylene glycol solution to obtain an air electrode slurry;

[0122] The outer layer of the electrolyte layer is covered with an air electrode 2 cm long by brushing or spraying;

[0123] After drying, it is sintered at 1000 °C for 2 h to obtain a solid oxide electrolysis cell unit.

[0124] S4. Loading the catalyst:

[0125] Nickel nitrate, copper nitrate, and cerium nitrate are accurately weighed according to a stoichiometric ratio of 1:2:3 and dissolved in deionized water. Citric acid is added, and the molar ratio of metal ions to citric acid is 1:1.5. It is uniformly stirred to form a 5 M catalyst slurry;

[0126] One end of the fuel electrode about 6 cm long, which is far from the solid oxide electrolysis cell unit, is placed in the catalyst slurry and impregnated under vacuum. After impregnation for 1 h, it is dried at 80 °C for 12 h and then sintered at 500 °C for 10 min; the catalyst impregnation step is repeated until the catalyst loading is 25% of the total mass of the reactor; after completion of impregnation, it is sintered at 500 °C for 4 h to obtain a hydrocarbon preparation unit, and a micro-honeycomb tube-type series reactor is obtained. Among them, copper elements exist in the form of cuprous oxide.

[0127] As an alternative, during the catalyst setting process, citric acid can be removed.

[0128] According to the same application method as described in Example 1, the analysis results of the gas at the outlet of the micro-honeycomb tube-type series reactor are shown in Table 3.

[0129] Table 3 Composition of the gas at the outlet of the series reactor in Example 3

[0130] <![CDATA[CO 2 > CO <![CDATA[H 2 > <![CDATA[CH 4 > <![CDATA[C 2 H 6 > <![CDATA[C 2 H 4 > <![CDATA[C 3 H 8 > 3.1％ 0.79％ 8.56％ 10.11％ 43.42％ 21.67％ 12.35％

[0131] Comparative Example 1

[0132] A preparation method of a single-channel tube-type series reactor for preparing methane in this comparative example. Under the condition that other process conditions and parameters are the same as those in Example 3, the difference is that the shell liquid and the coagulant are simultaneously extruded into water through a spinneret with a single core to obtain a fuel electrode embryo 18 cm long with a single channel. That is, a single-channel tube-type series reactor is finally prepared.

[0133] According to the same application method as described in Example 1, the analysis results of the gas at the outlet of the micro-honeycomb tube-type series reactor are shown in Table 4.

[0134] Table 4 Composition of the gas at the outlet of the series reactor in Comparative Example 1

[0135] <![CDATA[CO 2 > CO <![CDATA[H 2 > <![CDATA[CH 4 > 8.21％ 1.56％ 10.19％ 80.04％

[0136] As can be seen from Comparative Example 1 and Example 3, when the process and parameters of other preparation steps, including the type of catalyst, are the same, different numbers of channels in the tubular series reactor result in different products in the application of converting carbon dioxide and water vapor into hydrocarbons. This is because the multi-channel microcellular structure makes the distribution of reactants more uniform, thus providing suitable conditions for cuprous oxide to promote C-C coupling, and the microcellular structure makes the catalyst more dispersed, preventing the catalyst from agglomerating and avoiding the phenomenon of catalyst deactivation caused by agglomeration. Thus, the effective conversion of CO 2 / CO to high-value hydrocarbons such as ethane, ethylene, and propane is achieved. By adjusting the catalyst and the number of channels in this application, a mixture including methane, ethane, ethylene, propane, etc. is obtained, improving the value of the product.

[0137] Those of ordinary skill in the art can understand that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent substitution on some of the technical features. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a micro-honeycomb tubular series reactor for synthesizing hydrocarbons, characterized in that: include: The fuel electrode embryo is prepared by a phase inversion assisted extrusion method, and the spinning head used for extrusion has a plurality of needle cores, so that a plurality of channels are formed in the fuel electrode embryo; Sintering the fuel electrode embryo under high temperature conditions to obtain a fuel electrode (1) having a plurality of channels inside; An electrolyte layer (2) is arranged on the surface of the fuel electrode, and an air electrode (3) is arranged on the surface of the electrolyte layer (2) to form a fixed oxide electrolytic cell unit (4); A catalyst is loaded in the fuel electrode by an impregnation method to form a hydrocarbon production unit (5), which is distributed along the axial direction of the fuel electrode (1) with the fixed oxide electrolysis cell unit (4), thereby forming the series reactor; The catalyst is a copper-based catalyst, and the copper in the catalyst after loading exists in the form of cuprous oxide; The two axial ends of the fuel electrode (1) and the two axial ends of the air electrode (3) of the series reactor are respectively connected to an electrochemical workstation through silver wires. Under set temperature conditions, the series reactor is used to convert carbon dioxide and water vapor into hydrocarbons, and the hydrocarbons are a mixture of methane, ethane, ethylene, and propane.

2. The preparation method according to claim 1, characterized in that: The number of channels in the fuel electrode (1) is 4 to 7; the thickness of the thinnest part of the outer wall of the fuel electrode (1) is 50 to 80 μm.

3. The preparation method according to claim 1, characterized in that: The method of loading the catalyst in the fuel electrode by an impregnation method comprises: A mixture of copper nitrate or at least one of ruthenium nitrate, cerium nitrate and nickel nitrate and copper nitrate is uniformly mixed with deionized water in a certain proportion to obtain a catalyst solution; The portion of the fuel electrode (1) close to the first end is immersed in the catalyst solution, taken out after a set time, and then dried and sintered in sequence; The impregnation process was repeated until the catalyst loading was 25% of the total mass of the series reactors.

4. The preparation method according to claim 1, characterized in that: The electrolyte layer (2) is arranged on the surface of the fuel electrode, comprising: The yttria-stabilized zirconium oxide powder, polyvinyl butyral resin, polyethylene glycol, a dispersant, and an ethanol solution are uniformly mixed in proportion to form an electrolyte slurry; The electrolyte slurry is disposed on the circumferential surface of the fuel electrode (1) close to the second end thereof by dipping; Then carry out drying and sintering treatments in sequence.

5. The preparation method according to claim 1, characterized in that: The air electrode (3) is arranged on the surface of the electrolyte layer (2), comprising: The yttria-stabilized zirconia powder, the lanthanum-strontium-cobalt-iron powder and the ethylene glycol solution are uniformly mixed in a mass ratio of 5:5:6 to prepare an air electrode slurry; Spraying or brushing the air electrode slurry on the surface of the electrolyte layer (2); Then carry out drying and sintering treatments in sequence.

6. The preparation method according to claim 1, characterized in that: The method of preparing the fuel electrode embryo body by phase conversion assisted extrusion method comprises: Nickel powder, yttria-stabilized zirconium oxide powder, N-methylpyrrolidone and a dispersant are mixed in proportion and then ball-milled in a ball mill to obtain a first membrane liquid; adding polymethyl methacrylate to the first membrane liquid, and continuing to ball mill in a ball mill to obtain a second membrane liquid; The second membrane liquid is subjected to vacuum degassing treatment as the shell liquid, and the coagulant is used as the core liquid, which are simultaneously squeezed into water through the spinning head to obtain the fuel electrode embryo body.

7. The preparation method according to claim 6, characterized in that: The mass ratio of the nickel powder, yttria-stabilized zirconium oxide powder, N-methylpyrrolidone, dispersant and polymethyl methacrylate is (120-150): (80-100): (90-110): (1-2): (30-45).

8. The preparation method according to claim 1, characterized in that: The temperature for sintering the fuel electrode embryo under high temperature conditions is 1200° C.; the heating rate and cooling rate during the sintering process are 5° C. / min.

9. The preparation method according to claim 1, characterized in that: The set temperature condition includes: maintaining the solid oxide electrolysis cell unit (4) at 750°C, and forming a temperature gradient from 750°C to 150°C on the hydrocarbon production unit (5).

10. A micro-honeycomb tubular series reactor for synthesizing hydrocarbons obtained by the preparation method according to any one of claims 1 to 9.

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